DISEASE CHARACTERISTICS: Histologically proven refractory solid tumor or lymphoma requiring systemic therapy No standard therapeutic options exist Prostate cancer patients: Tumor progression during blockade of testicular and adrenal androgen required PSA elevation on 2 consecutive blood samples, 2 weeks apart Serum testosterone concentrations in the castrate range Leuprolide or other gonadotropin-releasing hormone (GnRH) analogs maintained if no prior orchiectomy No CNS neoplasms